I. Field
The following description relates generally to wireless communications, and more particularly to adaptive frequency planning in a distributed manner in a wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various types of communication; for instance, voice and/or data can be provided via such wireless communication systems. A typical wireless communication system, or network, can provide multiple users access to one or more shared resources (e.g. bandwidth, transmit power, . . . ). For instance, a system can use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), and others.
Generally, wireless multiple-access communication systems can simultaneously support communication for multiple access terminals. Each access terminal can communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to access terminals, and the reverse link (or uplink) refers to the communication link from access terminals to base stations. This communication link can be established via a single-in-single-out, multiple-in-single-out or a multiple-in-multiple-out (MIMO) system.
MIMO systems commonly employ multiple (NT) transmit antennas and multiple (NR) receive antennas for data transmission. A MIMO channel formed by the NT transmit and NR receive antennas can be decomposed into NS independent channels, which can be referred to as spatial channels, where NS≦{NT,NR}. Each of the NS independent channels corresponds to a dimension. Moreover, MIMO systems can provide improved performance (e.g., increased spectral efficiency, higher throughput and/or greater reliability) if the additional dimensionalities created by the multiple transmit and received antennas are utilized.
MIMO systems can support various duplexing techniques to divide forward and reverse link communications over a common physical medium. For instance, frequency division duplex (FDD) systems can utilize disparate frequency regions for forward and reverse link communications. Further, in time division duplex (TDD) systems, forward and reverse link communications can employ a common frequency region so that the reciprocity principle allows estimation of the forward link channel from reverse link channel.
Wireless communication systems oftentimes employ one or more base stations that provide a coverage area. A typical base station can transmit multiple data streams for broadcast, multicast and/or unicast services, wherein a data stream may be a stream of data that can be of independent reception interest to an access terminal. An access terminal within the coverage area of such base station can be employed to receive one, more than one, or all the data streams carried by the composite stream. Likewise, an access terminal can transmit data to the base station or another access terminal.
Resource planning (e.g., frequency planning, . . . ) is employed in wireless communication systems to allocate resources for use in connection with disparate base stations, where such allocation of resources is typically performed for interference management purposes. For instance, a first collection of resources can be used in connection with a first base station (e.g., for uplink and/or downlink transmissions, . . . ), while a second collection of resources can be utilized in connection with a second base station (e.g., for uplink and/or downlink transmissions, . . . ). Commonly, resource planning is effectuated in a centralized manner where each base station can obtain a predefined indication as to a collection of resource set(s) and/or a reuse factor to leverage when scheduling uplink and/or downlink communication; thus, a particular base station can employ a subset of overall available resources in the system based upon this predetermined indication.
Moreover, conventional resource planning techniques oftentimes apply to planned deployments. By way of example, in a planned deployment, coverage regions of different base stations can overlap in a predictable manner; thus, fractional frequency planning similar to frequency planning for classic reuse schemes can be used. Further, a reuse factor, which is a fraction of the total bandwidth to be used by a given base station, can be pre-computed in planned deployments based on deployment topology. However, common techniques typically are unable to account for poor interference conditions on the uplink and/or downlink that are encountered in an unplanned deployment.